The shorelines of most bodies of water suffer from a nearly inevitable tendency to erode. This phenomenon commonly is most pronounced in larger bodies of water such as oceans, and it is nearly always accelerated under severe weather conditions. Although such erosion could be of little consequence in certain locations, where seacoast communities have developed and where beaches are used for recreation and leisure, an eroding shoreline can lead to unfortunate, costly, and even catastrophic results. Many communities have seen coastal erosion march irresistibly shoreward to cause buildings to founder and topple into the sea and to decimate valuable beaches.
This erosion is the unfortunate result of the natural movement of currents and waves. It has been found that an ocean's current and wave movement actually gives rise to three main processes of shoreline particulate movement. A first process has been termed bed load transportation. Bed load transportation is the movement of large sand deposits by rolling or slipping along the ocean's floor. A second process of particulate movement, saltation, occurs when particulate matter briefly jumps from the sea floor only to fall into substantially its original location. The third process of particulate movement is termed transportation by suspension. Under transportation by suspension, particulate matter is drawn from the ocean floor to become suspended in turbulent water. The ocean's moving water often carries the suspended particulate matter a significant distance, commonly away from the shore, before redepositing it on the sea floor. Transportation by suspension is the main cause of erosion.
Recognizing this, numerous inventors have developed and disclosed devices intended to stem the eroding tendency of transportation by suspension while effectively attempting to exploit the nature of the particulate movement process to accomplish the generally contrary result of enhancing the accretion of particulate matter immediately adjacent to a shoreline. Although many solutions to shoreline erosion of this type have been proposed with each purporting to solve the problems left by its predecessors, their essential concept is consistent: to provide an artificial seaweed device with at least one strip of artificial seaweed that projects upwardly from the sea floor to reduce localized turbulence and to restrict the off-shore movement of waterborne particulate matter thereby reducing shoreline erosion and enhancing particulate accretion.
Such prior art devices undeniably are laudable for their goals, and they have been effective to varying degrees. However, prior art seaweed devices have been shown to exhibit a multiplicity of disadvantages that together render the seaweed devices significantly less effective than they might be otherwise. One recognized and longstanding problem detracting from the long-term effectiveness of prior art devices has been their tendency to exhibit extensive displacement migration or movement under adverse aquatic conditions. Research has shown that prior art artificial seaweed devices originally placed in long, shore-parallel rows often were spun to an ineffective orientation or dislocated and scattered or jumbled into ineffective groups. Furthermore, many prior art devices also have exhibited a tendency to roll along the sea floor under severe weather conditions thereby effectively reeling in the artificial seaweed strips upon which the effectiveness of the inventions relies. Ironically, this dislocation and possible anchor rolling of the seaweed devices has been found to be most prevalent where sand collection potential is greatest (i.e., on sand bars, groin tips, and heavily scoured beaches.
A number of solutions to the problem of displacement migration have been proposed (i.e., synthetic seaweed matrices in U.S. Pat. No. 4,641,997 and roped-together seaweed devices in U.S. Pat. No. 4,534,675). However, the very solution provided by these inventions has been seen to create another significant problem in the form of increased difficulty and complexity of installation. Since artificial seaweed devices are installed where aquatic conditions are turbulent, difficult installation procedures, particularly those requiring scuba personnel, are less than optimal.
More simply noted but of similar significance is the recognized tendency of adjacent artificial seaweed strips in many prior art devices to become entangled with one another. Once entangled, the strips present a diminished profile which leads to a resultantly lessened reduction of localized turbulence and a less effective barrier to particulate movement. Consequently, the entangled strips often fail to accomplish their intended purposes of reducing erosion and enhancing accretion of waterborne particulate matter.
With the aforementioned disadvantages of the prior art in mind and in light of the ever-increasing damage caused by coastal erosion, it becomes clear that there is a real and significant need for an artificial seaweed device that effectively prevents erosion while enhancing accretion of waterborne particulate matter, resisting undesirable dislocation and rolling, and preventing entanglement between adjacent artificial seaweed strips.